The present invention is related to an optical semiconductor device.
An optical semiconductor device having a semiconductor light-emitting element and a semiconductor light-receiving clement is widely used. The optical semiconductor device disclosed in the patent literature 1 detects whether there is a detection object in a specific area near the optical semiconductor device according to whether the semiconductor light-receiving element receives light from the semiconductor light-emitting element. In the situation that the semiconductor light-receiving element receives from the semiconductor light-emitting element directly, if the semiconductor light-receiving element received no light from the semiconductor light-emitting element, it is considered that there exists a detection object. However, in the situation that the semiconductor light-receiving element receives light from the semiconductor light-emitting element by reflection, if the semiconductor light-receiving element received light from the semiconductor light-emitting element, it is considered that there exists a detection object.
In the optical semiconductor device, it is required to improve miniaturization and enhance precision of detection.